Surfacing apparatus



June 18, 1963 E. T. DALTON 3,093,939

SURFACING APPARATUS Filed July 3, 1961 3 Sheets-Sheet 1 INVENTOIZ $5 3 Ise/vesr r DALTON ATTORNEY June 18, 1963 E. T. DALTON 3,093,939

SURFACING APPARATUS Filed July 3, 1961 3 Sheets-Sheet 2 [Ii-nu NV E NTOEERNEST Z DRLTON ATTO Q N EY June 18, 1963 E. T. DALTON SURFACINGAPPARATUS Filed July 3. 1961 3 SheetsSheet 3 &

I8Z H I I92 2 /92 /88 L ,9 I I A! a INVENTOIZ EENE ST 7? D01. TON

ATTORNEY United States atcnt Ofiice 3,093,939 Patented June 18, 19633,093,939 SURFACHNG APPARATUS Ernest T. Dalton, Southhridge, Mass,assignor to American Optical Company, Southbridge, Mass, an associationof Massachusetts Filed July 3, 1961, Ser. No. 121,786 16 Claims. (Ci.51-124) This invention relates to apparatus for surfacing articles suchas lens blanks or the like and has particular reference to improvementsin high-speed surfacing equipment which is designed more specificallyfor producing surfaces of compound curvature upon such articles.

Optical surfaces of compound curvature are usually formed on lens blanksor like articles by initially grinding a side of the blanks to apredetermined toric shape and thereafter optically polishing the groundsurface by placing the same in engagement with a preformed tool or lapor the like having a surface curvature matching that which has beenground upon the lens blank. The major meridians of the toric surfacecurvature on the lens blank are maintained parallel to the matchingmeridians of curvature on the tool at all times and a polishing mediumis applied to the tool surface so as to come between it and the surfaceof the lens blank to be polished. By producing relative motion betweenthe lens blank and tool Without disturbing the parallel relationship ofthe above-mentioned meridians, the surface of the lens blank ispolished.

In general, the time required to produce a polished surface of opticalquality is dependent upon the amount of relative motion which can beproduced between the lens blank and toolwithout destroying the accuracyof the compound surface curvature and the rate at which the motion isimparted. That is, with other factors such as the texture of theinitially ground surface, the pressure applied to the work piece and theparticular characteristics of the polishing medium being considered tobe the same in all cases, greater amounts of relative motion and fasterspeeds thereof will reduce the polishing time accordingly.

In certain practices, lens blanks having relatively rough (groundsurfaces are fine ground before polishing and this fining operation isusually accomplished in the manner described above for polishing simplyby substituting a grinding medium for the above-rnentioned polishingmedium.

In toric surfacing operations, the respective major and minor meridiansor axes of the compound surface curvacure on a toric lens blank beingprocessed must be maintained parallel to the respective matchingmeridians or axes of the preformed :toric working surface of the tool atall times and, because of this, relatively complex and ungainly harnessarrangements or the like have been used heretofore to support and retainthe lens blanks and tools in proper oriented relation with each otherduring surfacing operations. The complex nature of prwently usedaxis-aligning devices has not made it possible to provide a balancedpiece of equipment which could be operated at relatively high speeds.That is, conventional axis-aligning devices have comprised variousoff-set arms and yokelike holding members or the like for supportingeither the tool or work piece and at least some of these members havebeen resiliently or otherwise movably held by flexible arms or pivotalconnections or the like. When rotated at relatively slow speeds, devicesof this type perform their intended function but, at high speeds ofrotation, centrifugal forces and other effects such as vibration due toimbalance of the equipment cause mis-alignment of the Work holder andtool during surfacing with the result of producing inaccurately curvedand poorly textured surfaces or otherwise inferior lens blanks.

In order to keep abreast with the ever increasing demands for moreefficient and increased production in the lens manufacturing field, itis essential that lens blanks surfacing operations be speeded up andimproved without sacrifice of end product quality and with a view toimproving product quality. This, obviously, cannot be accomplishedsuccessfully with conventional equipment designed for relativelyslow-speed operations and wherein the problems of balance and otherdesign factors essential to high-speed operations were not properlydealt with.

The present invention, in dealing with the factors involving high-speedsurfacing methods and operations, offers a solution to theabove-mentioned and other problems in this field and, accordingly, it isa principal object of the invention to provide novel means for surfacingtoric lens blanks or like articles with increased efiiciency andprecision.

Another object is to provide, in surfacing equipment of the abovecharacter, an improved rotatable tool and Work supporting arrangementdesigned for substantially centrifugally balanced operation when rotatedat relatively high speeds.

Another object is to provide, as a part of said tool and work supportingarrangement, novel resilient holding means for supporting a work piecein fixed oriented relation with an abrading tool at all times whilepermitting a substantial amount of freedom of lateral oscillatorymovement between said workpiece and tool without sacrifice of productquality.

Another object is to provide a tool and work holding device of the abovecharacter for supporting a tool member and work member in abradingrelation with each other and which is rotatable as a unit about a. fixedaxis, said device embodying an inner rigid support for a first of saidmembers positioned coaxially with said axis of rotation and an outerresilient support surrounding and attached to said rigid support at oneend with its opposite and being free and adapted to receive and supportthe other of said members in relatively free floating fashion upon saidfirst member.

Another object is to provide a work holding device of the abovecharacter wherein said outer resilient support is constructed andarranged so as to be in balance and substantially concentric with theaxis of rotation of the device and is so characterized as to resisttortional or other forces tending to produce orbital mis-alignment ofits opposite ends while being otherwise universally flexible.

Another object is to provide as said outer resilient support, a coiledspring-shaped member having convolutes so geometrically proportioned asto render said member substantially immune to centrifugal and tortionalor other forces tending to produce orbital misalignment of theconvolutes thereof under the greatest rotational rates and pressures towhich said member might be subjected during an abrading operation.

Another object is to provide, as a substitute for said spring-likemember, a cylindrical bellows-type of structure.

A further object is to provide through the use of arrangements such asgeneralized above, simple, highly efficient and economical toricsurfacing apparatus which is designed to perform high-speed opticalsurfacing operations with precision, dependability, and unusualefiiciency.

Other objects and advantages of the invention will become apparent fromthe following description when taken in conjunction with theaccompanying drawings in which:

FIG. 1 is a perspective illustration of a lens blank which is to befinished in accordance with this invention;

FIG. 2 is a perspective view of a preferred lap or tool used inconjunction with the apparatus of the invention for finishing a surfacecurvature upon a lens blank or the like such as shown in (FIG. 1;

3 =FIG. 3 is a side elevational view of a preferred form of surfacingapparatus with portions broken away to reveal featured sections thereof;

,FIG. 4 is a front elevational view of the apparatus shown in FIG. 3;FIG. 5 is an enlarged cross-sectional view taken approximately alongline 5-5 of FIG. 3 looking in the direction of the arrows; FIG. 6 isa'view of a portion of the apparatus shown in FIG. 3 taken from theposition of line 66 on FIG. 3 and looking in the direction indicated bythe arrows;

FIG. 7 is an enlarged fragmentary cross-sectional view takenapproximately along line 7--7 of FIG. 5;

FIG. 8 is a view generally similar to FIG. 7 showing an alternativearrangement of that portion of the apparatus; and

FIGS. 9, 10, 11 and 12 are fragmentary views of different modificationsof the invention.

The'present invention relates generally to apparatus for surfacingarticles such as lens blanks or the like and the drawings illustrate apreferred form of such equipment in which is featured a novel lens blankand tool supporting fixture 20 (see FIGS. 3, 4, and 5) for holding alens blank and tool in fixed pro-established orbitally aligned relationwith each other at all times. It will become apparent hereinafter thatthe fixture 20, which is rotated as a unit during a surfacing operation,provides a well balanced piece of rotary equipment which permtishigh-speed operations to be accomplished with a minimum of vibration orother effects of imbalance which would be detrimental to the accuracy ofcurvature and facing machines but, for purposes of illustration, it hasbeen shown in FIGS. 3-7 in a position of use on a preferred form ofapparatus wherein the combination of the apparatus illustrated and thefixture 20 provides a unique, compact and highly eflicientlens-surfacing machine 22. The apparatus upon which the rotary fixture20 is mounted will be described in detail first to provide a betterunderstanding of the construction, purpose and function of the fixture20 whose description will follow.

Referring more particularly to (FIGS. 3 and 4, it will be seen that thesurfacing machine 22 comprises a base 24 preferably having a hollowinterior and an overhanging head part 26 pivotally connected to the base24 by means of H-shaped links 28 and 30 (see FIGS. 3 and 4) which arepivotally attached to pivot blocks 32 and 34 on the respective head andbase parts of the machine. The blocks 32 and 34 and their respectivelinks 28 and 30 are interconnected by pivot pins '36 and the blocks 34are bolted or otherwise fixed to the base 24. The blocks 32, which willbe considered to be a part of the head 26, are interconnected byhorizontally disposed rods 38 and 40 which are fitted into bores 42 and44 respectively in enlarged bosses 46 formed on the uppermost portion ofeach of the blocks 32. The rods 38 and 40 are securely clamped adjacenttheir opposite ends in the bosses 46 of the blocks 32 by set screws orthe like 48 and are so arranged (see FIG. 4) as to place the uppermostends of the links 28 and 30 at a distance apart which is substantiallyequal to the distance between the lowermost ends of said links.

The composite arrangement of the links 28 and 30, the pivot blocks 32and the rods 38 and 40 [forms a cradle upon which an overhanging portion50 of. the head 26 is mounted so as to pivot about the rod 38. Thecradle, being so pivotally mounted to the base 24, provides means foroscillating the head 26 laterally or in a sidewise direction during asurfacing operation as will be explained in detail hereinafter. Theoverhanging portion 50 of the head 26 embodies a main supporting casting52 which is provided with a pair of depending split bearings 54 fittedto the forward rod 38. The bearings 54 are so machined and fitted to therod 38 as to provide a secure, vibrationless connection while permittingrelatively free pivotal movement of the overhanging portion 50 of thehead 26 about said rod 38. The overhanging portion 50 of the head 26,while being free to pivot about the rod 38 is fixed against lateralmovement along the rod 38 by means of suitable stop means which, forpurposes of illustration, is shown as being a collar 51 surrounding therod 38 between the split bearings 54. Once the overhanging portion 50 ofthe head 26 is placed at a desired location along the rod 38, the collar51 is locked to the rod 38 by set screws or the like 51a.

It is pointed out at this time that all pivotal or solid connectionswhich are made between the various parts of the machine 22 areaccurately machined so as to provide intimate, secure and vibrationlessconnections. Furthermore, the various parts described hereinabove andthose to be subsequently described are designed to be of such rigidityas to minimize vibrations during the operation of the machine.

Referring again to the overhanging portion 50 of the head 26, it will beseen in FIGS. 3 and 4 that there is attached to the forward end of thecasting 52, a spindle housing 56 in which is journaled a rotatablespindle 58 (see FIG. 5). The spindle 58 will be referred to hereinafteras the upper spindle and it is driven by a motor 60 through pulleys 62and 64 and an interconnecting belt 66. The motor 60 is mounted upon thecasting 52 adjacent the rear portion of the head 26 so as to partiallycounterbalance the portion of the head 26 which overhangs the forwardsection of the machine.

The spindle housing 56 is provided with an integral 'rearwardlyextending mounting bracket 68 which is attached to the casting 52 with abolt 70. The adjoining surfaces of the mounting bracket 68 and thecasting 52 are arcuately shaped and matched in curvature to fittogether. These arcuate interfitting shapes of the casting 52 andbracket 68 permit the spindle housing 56 to be tilted slightly bysliding the spindle housing mounting 'bracket168 to one side or theother of a mid-position where the housing axis would normally bevertical. A slot 72 in the mounting bracket 68 allows for a desiredlateral adjustment of the spindle housing and'the bolt 70 is immovablymounted in the casting 52 so that, by loosing the nut 71, the spindlehousing bracket 68 is free to slide laterally for purposes of adjustingthe tilt of the spindle housing. When a desired adjustment is made, thenut 71 is tightened to retain the adjustment. The respective surfaces 74and 76 of the casting 52 and mounting bracket 68 are curved to a radiusr (see FIG. 4) approximately equal to the distance between said surfacesand a point 77 therebelow approximately at the level of the averagecenter of curvature of a lens blank surface to be worked upon in thefixture 20. This will be discussed in greater detail hereinafter whereinit will become apparent that the particular curvature of the surfaces 74and 76 are arranged to cause the spindle housing to be tiltedapproximately radially about the center of the average curvature of alens blank surface to be worked upon. This is to cause the axis of thespindle 58 to be directed approximately normal to a tangent to the lensblank surface at the point of intersection of the upper spindle axiswith said lens blank surface and thus pressure exerted upon the lensblank by the head 26 is directed substantially evenly during lateraloscillation of the lens blank as a surfacing operation is performed.This will be explained in greater which the member 88 is threaded (seeFIG. 3).

detail hereinafter in conjunction with a description relating to theoperation of the apparatus of the invention.

, In order to lift and lower the overhanging portion 50 of the head 26so as to permit the insertion or removal of work pieces from the fixture20, an air cylinder 78 is secured by bolts or the like 80 to the rearside of the base 24 and its piston rod 82 is connected to the casting 52of the head 26 by a flexible cable or cord or the like 84. When the aircylinder 78 is actuated, its piston rod 82 is drawn downwardly producinga pull on the cord 84 which causes the overhanging portion 50 of thehead to pivot on the rod 38 and lift the spindle housing away from thefixture 20. With the machine in operating position, the piston rod 82 ofthe air cylinder 78 is raised as shown in FIG. 3 to provide slack in thecord 84 thereby allowing spindle housing 56 to lower to an operatingposition wherein the lens blank will freely engage the tool. Since it isrequired that a controlled pressure he applied to a lens blank or workpiece which is being surfaced, a spring 86 is connected under tensionbetween the base 24 and the overhanging portion 50 of the head 26. Thespring 86 is held under tension by hooklike members 88 and 90 attachedto its opposite ends and the member 90 is secured with a bracket 92 tothe base 24 while the member 88 is adjustable vertically to increase ordecrease the tension of the spring 86. This adjustment is accomplishedby means of an internally threaded adjusting bolt 94 iInlto e bolt 94is, in itself, rotatable in a vertical sleeve-like fitting 96 which isintegral with the casting 52. Rotation of the "bolt 94in the fitting 96causes the threaded portion 93 of the hook-like member to advance intoor retract from the internally threaded area of the bolt 94 (dependingupon its direction of rotation) so as to bring about a raising orlowering of the hook-like member 88 to increase or decrease the tensionof the spring 86 as required.

The machine 22 is provided with a lower spindle housing 100 whichisbolted or otherwise attached to the upper portion of the base 24 (seeFIGS. 3, 4 and 5) and extends upwardly through the top of the base 24toward the upper spindle 58.

In the lower spindle housing 100, there is journaled a lower spindle 102{see FIG. 5) which is rotatably driven by a motor 104 through a belt andpulley arrangement embodying a pulley 106 on the motor 104, a pulley 108connected to the lower spindle 102 and an interconnecting belt 110.

The upper and lower portions of the lower spindle 102 are journaled inthe housing 190 by means of bearings such as shown at 112 in FIG. 5 andthe uppermost end of the spindle 102 is threaded at 114. A first adaptor116 is threadedly connected to the upper end of the spindle 102 so as tobe rotatable therewith and a second adaptor 118 for receiving andsupporting a tool 129 is also carried by and rotatable with the lowerspindle 102. This second adaptor 118 which will be referred tohereinafter as the tool adaptor 118 is provided with a tapered uppersection 122 for receiving the tool 120 and has an intermediate annularshoulder 124 with a reduced cylindrically shaped depending portion 126which is fitted into a similarly shaped recess 123 formed in the upperend of the spindle 102. The tool adaptor 118 is held in place on thespindle 102 by means of a bolt 130 which extends substantially coaxiallytherethrough and is threaded into the spindle 102 adjacent the base ofthe recess 128 therein. The head of the bolt 130 is recessed into thetool adaptor 118 as shown in FIG. 5 and a locating pin 132 which isfixed in the spindle 102 so as to extend upwardly into the recess 128 isarranged to enter a receiving opening 134 in the tool adaptor 118 tolocate the adaptor in a fixed predetermined oriented relation withspindle 102. The locating pin 132 also functions to prevent possiblerotational misalignment or slippage between the spindle 102 and toolrequired in a surfacing operation.

adaptor 118 thereby assuring that the adaptor and spindle will rotatetogether as a common unit and the holding bolt will not tend to becomeloosened. Also, on the tool adaptor 118 there is provided a keying pin136 (see FIG. 3) which is press-fitted or otherwise secured in anappropriately formed lateral opening 137 in the tapered section 122thereof. The tool 120 which has an axially aligned tapered opening 138adapted to interfit with the tapered section 122 of the adaptor 118 isprovided with a key slot 140 (see FIGS. 2 and 3) which fits over the pinwhen the tool 1120 is placed upon the adaptor 118. The key slot and pin136 prevent rotational slippage from taking place between the tool 124}and adaptor 118 and the combination of the above-described parts causesthe spindle 120, adaptors 116 and 118 and tool 120 to rotate together asan integral or common unit when the spindle 102 is rotated.

The fixture 211 which will be considered herein to include the adaptors116 and 1 18 and the tool 120 further comprises an annular base plate142 which is fitted onto a shoulder 144 formed on the first adaptor 116as shown best in FIG. 5. The base plate 142 is secured to the firstadaptor 116 by connecting bolts or studs 146 and is shaped to have anouter annular platform-like portion 147 depending from the points of itsconnection to the adaptor 115. This platform portion 147 is concentricwith the axis of the spindle 102 and carries an upstanding resil ientcoupler 148 which supports and resiliently connects an upper workholding assembly 150 to the base plate 142 of the fixture 20.

The coupler 148, in its preferred form as shown in FIGS. 3, 4 and 5, isconstructed of a resilient metal such as cold rolled steel, stainlesssteel or other alloys common to the manufacture of articles such ascoiled springs and, being in the general configuration of a coil spring,the coupler 148 is constructed in accordance with known techniques usedin the manufacture of such items so as to have a desired degree ofrigidity in tending to naturally support the work-holding assembly 150at a desired level relative to the total 120 while also being relativelyfreely and substantially evenly or equally flexible in all meridians topermit its uppermost end to move laterally and tilt as The coupler 148is further characterized to be relatively easily compressible forpurposes of permitting the work piece to remain in engagement with thetool at all times during a. surfacing operation as will be explainedmore in detail hereinafter.

The coupler 14$ is, in addition to the above, characterized to besubstantially immune to tortional forces tending to wind or unwind itsconvolutes 152 as a result of pressures applied between the work pieceand tool 120 or forces caused by rotation of the fixture at relativelyhigh speeds during operation of the machine 22.

These characteristics of the coupler 148 are achieved by proper designof the shape and size of the convolutes 152 in accordance with thematerial used in its construction.

By way of example, it has been found that a coupler 148 such as shown inFIGS. 3, 4 and 5 which is formed of cold rolled steel or stainless steelto an outer diameter of approximately 6 inches should have convolutes 152 measuring approximately from /s to inches in thickness andapproximately /8 inches in width, giving the coupling 148 an innerdiameter of approximately 4% inches. If formed of other metals, thesedimensions would be adjusted in accordance with the particularcharacteristics of the metals selected. The coupler 148 is alsopreferably constructed so as to have a right-hand wind with a pitch ofabout of an inch. It is intended to be rotated clockwise, as viewed fromabove, when driven by the lower spindle 102 since it has been found thatarticles of this nature are more resistant to orbital mis-alignment oftheir opposite ends when rotated in the direction of their wind. Thelowermost convolute 154 of the coupler 148 is fixed to the base plate142 by bolts or studs or the like 156 most convolute 158 of the coupler148 by the bolts or studs 160. Thus, it can be seen that rotation of thespindle 102 will cause the entire fixture 20 including the tool 120 andwork-holding assembly 150 to rotate as a unit; the work-holding assemblybeing driven from the base plate 142 through the resilient coupler 148.

In detail, the work-supporting assembly 150 comprises an annulus 162which is attached to the uppermost convolute !158 by the studs 160. Theannulus 162 is provided with a recess 164 into which a rotatableadjustable collar 166 is coaxially fitted (see FIGS. 4, 5, and 6). Thecollar 166 is held in place on the annulus 162 by a pair of lockingstuds 168 extended downwardly through slots 170 provided in the collar166. The studs 168 are threaded into the recessed portion of theannulus. In FIG. 6, it can be seen that the slots 170 are arcuatelyshaped to a curvature concentric with the common axis of the annulus 162and collar 166 so that, with the studs 168 loosened, the collar 166 maybe rotated upon the annulus 1 62 within the limits of the slots 170 toadjust the orientation of the collar relative to the tool 120.

In the fabrication of this part of the fixture 20, the collar 166 isfitted to the annulus 162 in a predetermined oriented relation withrespect to the tool 120 and the annulus is then drilled and tappedapproximately mid-way between the ends of the slots 170 so that, for afine or more precise alignment inorientation of the work piece holder150 relative to the tool, the above-mentioned adjustment using the studs168 and slots 170 may be used in the final adjustment of the fixture 20.This will be explained in more detail in the description of the settingup and operation of the machine 22 which follows.

The collar 166 is provided with a pair of diametrically opposed raisedsections 172 through each of which is provided an accurately machinedbearing opening 174. These bearing openings 174 are coaxial along adiameter of the collar 166.

A work-supporting yoke 176 is extended between the openings 174 and issupported at its opposite ends by bearing studs 178 which are threadedthereinto (see FIG. The enlarged heads 180 of the studs are carefullymachined to fit closely in the openings 174 which function as bearingsurfaces for said heads 180 and the yoke 176 is free to pivot about thecommon axis of the openings 174.

It is pointed out that in order to minimize wear, it is preferable toform the collar 166 and bearing studs 178 of different metals. That is,for example, one of bronze and the other of steel. It is further pointedout that while it is preferable to form practically all parts of themachine 22 of metal, the selection of materials used is made in theconventional manner of machine designing to obtain optimum performancewith minimum wear.

The yoke 176 has an enlarged mid-portion 182 in which is centrallylocated a recessed ball socket 184 adapted to receive the ball-shapedend portion of a crank pin 186 carried by the upper spindle 58. 'It willbe noted in FIGS. 4 and 5 that the crank pin 186 is locatedeccentrically in the depending end of the upper spindle 58 so thatrotation of the spindle 58 will cause the crank pin 186 to orbit and,

- when seated in the bearing socket of the yoke, it will cause thework-holding assembly 150 to move accordingly. The work-holding assembly150, being supported by the rresilient coupling 148 is, of course, freeto respond to the orbiting of the crank pin 186.

A work piece such as the lens blank L is supported with its surface swhich is to be abraded against the surface t of the tool 120. The lensblank L which ordinarily would be attached to a block 188 as shown inFIGS. 5 and 7 is supported in abrading relation with the tool 120 bymeans of aligning and holding pins 190 in the yoke 176 which interfitwith sockets 192 in the block 188. The lens blank L may be blockedeither in the more conventional manner by attaching :the same with pitchor some such adhesive to a ready formed block which resemblesthe block188 and has sockets like those shown in FIG. 7 or by casting the block188 directly upon the lens blank L as shown in the drawings. Thistechnique is known in the trade and employs the use of low-meltingtemperature alloys. One of such alloys is known commercially asCerrolow. In blocking thisway, a new block is formed for each surfacingoperation and the sockets 192 (see FIG. 7) that are formedsimultaneously as the block is cast are not subjected to appreciablewear since the block is used only once. Each time a blocking operationis required, a newblock is cast upon the lens blank with newly formedsockets 192.

In referring more particularly to the setting up and operation of themachine 22 in the surfacing of a compound or toric curvature upon a workpiece such as the lens blank L (FIG. 1), it is pointed out that thisinvention relates more particularly to the finishing of a lens blanksurface by polishing and wherein the lens blank surface has beenpreformed by previous conventional grinding or generating operations toa true toric surface shape. Such a lens blank (as shown in FIG. 1)embodies the compound surface curvature s having a base meridian and acylinder meridian which, for purposes of illustration, have beenindicated diagrammatically by the respective lines b and c. The base andcylinder meridians are referred to as such in the trade wherein it isgenerally understood that the axis of the weaker curvature of a toricsurface, which is sometimes called the spherical curvature, is the basemeridian and the axis of the more severe or stronger curvature isreferred to as the cylinder meridian. These axes or meridians b and care, of course, disposed at right angles to each other and intersect atthe center 0 of the lens blank.

In blocking a lens blank such as shown in FIG. 1 to a block 188, it isgenerally the practice to align the cylinder axis c of the lens blankparallel to a 'line passing centrally through the sockets 192 so thatwhen the blocked lens blank is supported in the fixture 20 with theholding pins 190 of the yoke 176 placed in the sockets 192 of [theblock, the cylinder meridian c of the lens blank will be disposed normalto or at right angles to the axis of the opposing arms 175 of the yoke176 and the base meridian b of the lens blank will be disposed parallelto the axis along the opposing arms 175 of the yoke 176.

It is po'mted out that the usual procedure in making toric lens blanksis to provide the lens blank with a block 188 prior to the initialgenerating or grinding of the toric surface s thereon and the toricsurface s is formed with its base and cylinder meridians in theabove-mentioned known relation to the sockets 192 in the block 188.Without being reblocked, the lens blank is then ready for surfacing inaccordance with this invention.

In any case, this invention does not relate to the initial generating ofthe tonic surface s but does relate to the finishing of said surface bya surfacing operation which may be either a line grinding or a polishingoperation or both where the latter operation follows the former.

The process of the invention begins with the blocked lens blank L havinga ground true toric surface s thereon.

The tool (FIG. 2) which is used in the performance of the surfacingoperation is provided, as pointed out above, with a true toric workingsurface 2 which is of the final curvature desired on the lens blank andwhich, for all practical purposes, accurately matches the initiallyground compound or toric surface curvature s of the lens blank.

As shown more clearly in FIG. 2, the working surface t of the tool 120has a base meridian of a curvature matching that of the base curvatureof the lens blank L and a cylinder meridian of a curvature matching thatof the cylinder curvature of the lens blank L. The base and cylindermeridians of the working surface t of the tool 120 are shown, forpurposes of illustration, by the respective lines b and c and it will benoted in FIG. 2 that the location of the cylinder meridian c' of thetool surface t is indicated by a notch 196 at the tool edge. Also, thekey slot 140 in the tool 120 is located in parallel alignment with thecylinder meridian of the surface t so that when the tool 120 is appliedto the tool adaptor 118, its key slot 140, in fitting over the pin 136,will locate the cylinder axis of the tool surface t in a fixed directionparallel to a line through the pins 190 in the yoke 176. This,therefore, aligns the meridians c and c of the lens blank surface s andthe tool surface 1 parallel to each other and the lens blank L and tool120 are retained in this orbitally aligned relation throughout thesurfacing operation.

In the event that this parallel relationship of the respective meridiansof the lens blank and tool is not precisely achieved in the initialset-up of the fixture 20, the studs 168 are loosened in the collar 166and the collar 166 is rotatably adjusted as described above to align theaxis of the arms of the yoke perpendicular or normal to the meridian cof the tool 120. The studs 168 are then tightened to permanently lockthe collar 166 in place.

It is pointed out that placement of the blocked lens blank in thefixture 20 is accomplished simply by lifting the yoke 176 away from thetool 120 an amount sufficient to permit the blocked lens blank to bepositioned between the yoke and tool. The sockets 192 in the block 188are aligned with the pins 190 in the yoke and the yoke is lowered toposition the pins 190 in their respective sockets 192 in the blockthereby holding the lens blank against the tool. Removal of a finishedlens blank is accomplished by again lifting the yoke 176 to release thepins 190 from the sockets 192 whereupon the blocked lens blank is takenout of the fixture from between the yoke and tool.

As it can be seen from the drawings, the entire fixture 20 is rotatedduring a surfacing operation while the yoke 176 holds the blocked lensfixed against rotation in the fixture 20 and the interfittingrelationships of the pin 136 and key slot 140 hold the tool fixedagainst rotation in the fixture.

In performing a polishing operation with the device of the invention, arelatively thin polishing pad 198 is attached to the surface t of thetool 120 so as to cover the said surface andybe disposed between it andthe surface s of the lens blank L to be worked upon. The pad 198 isselected to be of such character as to conform accurately to the shapeof the tool surface t and is preferably secured thereon with apressure-sensitive adhesive or any cement or the like ordinarily usedfor this purpose. The polishing pad is preferably formed of a materialknown to the trade as Pellon or any similarly characterized material. Acommonly known felt polishing pad may be used or others formed ofplastics.

In producing action or relative movement between the lens blank and toolfor purposes of polishing, the fixture 20, as a whole, is rotated by thelower spindle 102 while the upper spindle 58 is rotated to orbit thecrank pin 186 and produce a first relative lateral movement between thelens blank L and tool 120. The crank pin being orbited about a circularpath while the fixture is rotated causes the lens blank to movegenerally spirally over the surface of the tool 120.

It has been found that for surfacing the average size of lens blank,good polishing action is achieved by offsetting the axis of the upperspindle approximately 7 /2 millimeters from the axis of the tool whileproviding an offset of the crank pin 186 from the axis of the upperspindle of approximately 2 /2 millimeters giving the crank pin anorbital path of approximately 5 millimeters in diameter. These figuresare arbitrary and obviously can be varied considerably. It has also beenfound that good results of surface quality are obtained by rotating theupper spindle at approximately 60 revolutions per minute whilesimultaneously rotating the lower spindle 1i) and fixture 20 atapproximately 600 revolutions per minute.

It should be clear that ability of the coupler 148 to flex as requiredpermits the upper end of the fixture 20 to freely follow the movement ofthe crank pin 186 in producing lateral motion between the lens blank Land tool 120. An additional break-up motion is imparted to the lensblank L by oscillating the entire head 26 of the machine 22 sidewisethrough the use of the abovedescribed linkage which connects the head 26to the base 24-. In FIG. 4, it can be seen that the link 30 is providedwith a lateral extension 200 to which a depending crank arm 202 ispivotally connected at 204. The lower end of the crank arm 202 issimilarly piv-otally connected at 206 to a rotatable camming plate 208which is driven by a motor 210. An adjusting slot 212 in the cammingplate 208 permits the connection 206 to be made at a predeterminedspaced location from the axis of rotation of the plate 208 so that theextent of sidewise motion, or oscillation of the machine head 26 can beadjusted as desired. That is, the throw resulting from the eccentricityof the connection 206 relative to the axis of the plate 298 operates thecrank arm 202 to raise and lower the same with each revolution of theplate 208. This pivots the link 30 in its pivot blocks 32 and 34 therebycarrying the head 26 in an oscillating sidewise or cross-motion as themotor 210 is operated. A cross-motion of approximately 5 millimeters hasbeen found to produce desirable results. Again, it: is pointed out thatthe free flexing ability of the coupler 148 permits the upperwork-supporting portion of the fixture 20 to follow all motions impartedthereto by movement of the head 26 and rotation of the upper spindle 58while, at the same time, the coupler 148 being immune to tortional orother forces tending to wind or unwind the same, holds the respectivebase and cylinder meridians of the lens blank L and tool parallel toeach other at all times.

It has been found that, for most polishing operations, a downwardpressure of the work piece or lens blank L upon the tool surface ofapproximately 35 lbs/sq. in. produces desirable results and thispressure is applied by controlled adjustment of the spring 86 asdescribed hereinabove. Also, in order to direct said pressuresubstantially along a line through the center of curvature of the lensblank and which is substantially normal to the average plane of thegeneral curvature of the tool surface at the point of intersection ofsaid line therewith, the upper spindle housing 56 is tilted or inclinedas shown in FIG. 5 by adjustment of its supporting bracket 68 upon thearcuately shaped surface 74 of the head 26 as described hereinabove.

Once this adjustment is made, the upper spindle housing is locked inplace 'by the nut 71 on the bolt 79'.

In the operation of polishing a lens blank L when the machine 22 isoperated as described above with the polishing pad 1% upon the toolsurface I, a fluid polishing medium is applied to the pad 198 preferablycontinuously during the polishing operation so as to come between thelens blank surface and the pad. Any of the well-known and commerciallyavailable polishing mediums may be used. The selection of a polishingmedium would be made in accordance with the material of the work piecewhich may be a glass lens blank or, in some cases, a plastic lens blank.Suitable commercially available polishing mediums for both plastics andglass are well known in the trade.

The polishing medium is applied to the tool and lens blank by means of afeed line or tube 216 (see FIG. 4) carried by the head 26 of the machinewith its fluidemitting end 218 directed into the fixture 20 toward theworking surface of the tool 120. The tube 216 is attached to the upperspindle housing 56 or may be attached to any convenient part of the head26.

In order not to hinder the sidewise oscillation of the machine head 26,the tube 216 is preferably formed of conventional flexible tubing orhose material and it is directed from the'head 26 to a suitable pump 220placed in a container 222 which holds a supply of the polishing medium.The container and pump may be placed within the machine base 24 as shownin FIG. 4 or at any location convenient to the machine.

A splash covering 224 is provided around the fixture 20 and is designedto collect used polishing medium and direct the same back to thecontainer 222 for re-circula-- tion. A collecting and return tube 226(FIG. 3) extends from the covering 224 for this purpose.

A modification of this portion of the invention is shown in FIG. 12wherein the fixture 20 and its adjacent associated parts are containedwithin a bowl 228 which carries the fixture 20 and is mounted upon thelower spindle 102 of the machine 22 so as to be rotated thereby. In thisaspect of the invention, the liquid polishing medium is placed in thebowl and, by centrifugal forces caused by rotation of the bowl, themedium is urged against its sides. A stationary collector or scraper 230is mounted adjacent the inner side of the bowl 228 by means of a bracket232 fixed to the base 24 of the machine and the scraper acts to scoop upor collect the polishing medium at the sides of the bowl causing thesame to be effectively thrown outwardly through an outlet tube 234 backonto the fixture 20 and upon the work piece and tool.

From the above, it should be clear that the fixture 20 provides anexceptionally well balanced piece of equipment which may be rotated athigh speeds while the respective base and cylinder meridians of theadjoining surfaces of the lens blank and tool are accurately maintainedparallel to each other at all times during the operation of the machine.At the same time, the resilient coupler 148 which acts to maintain thisaligned relationship of the tool and work piece allows the work piece tomove freely relative to the tool in lateral directions for inducing anabrading or polishing action on the Work plece.

It is pointed out that if the machine 22 is to be used to fine grind thesurface of the lens blank L rather than to polish said surface, thepolishing pad 198 would not be used. That is, the lens blank L would beplaced in direct engagement with the tool surface t and a liquidabrasive medium such as one containing emery particles suspended inwater or a suitable vehicle would be used to replace the polishingmedium. Otherwise, the operation would be performed identically to thatdescribed above for polishing. Certain relatively thin coverings ofscreening material or the like which are conformable accurately to thetool surface 1 may be used to protect the. tool surface if desiredduring a surfacing operation Where an emery abrasive material is used.Such coverings would simply replace the polishing pad 198 and thusprotect the surface t of the tool from wear.

It will be noted that in FIGS. 1-7, the concave or negative side of thelens blank has been shown as being polished or worked upon and the lensblock has been shown as being supported by the yoke 176. Thisarrangement may be reversed as shown in FIG. '8 so that the convex orplus side of a lens blank L can be readily abraded or polished with theapparatus disclosed herein. In so doing, the work-holding member 236which resembles the tool 120 in practically all respects is used tosupport the work piece or lens blank L, The member 236 is placed in thefixture 20 in a manner identical to that described above for the tool120. The lens blank L, however, is blocked upon the work-holding member236 with a suitable adhesive 238 such as pitch or the like or alow-melting temperature metallic alloy.

The tool 240, in this case, resembles the block 188 in practically allrespects and is supported by the yoke 176 in a manner exactly asdescribed with relation to the block 188. The surface of the tool 240which engages the lens blank L' is provided with a'toric shape matchingthat of the plus side of the lens blank and may or may not be providedwith a polishing pad 242. The polishing pad 242 would be used for apolishing operation and not used for a fine-grinding surfacing operationwith loose abrasives such as emery or the like. When using emery or thelike, a wire mesh may replace the polishing pad, if desired.

The operation of the apparatus in surfacing the plus or convex sides oflens blanks as shown in FIG. 8 is identical to that used for surfacingthe concave sides of lens blanks and, in essence, only involves areversal of the tool and work-holding means. It is pointed out that thesurfacing of a plus or convex side of a lens blank could be achievedwithout the reversal of .tool and work holder by providing a tool havinga concave toric working surface in place of the convex surface I of tool120.

The novel method of abrading a compound surface on an article whichcomprises supporting said article and an abrading member in abradingrelation with each other, moving said member and said article relativeto each other in irregular paths while retaining the major meridians ofsaid member and article in parallel relation with each other and ofbalancing the effect of centrifugal force on said member and article toobviate vibration and rnis-alignment of said member and article duringsaid abrading operation results from forming the means for retaining thearticle and abrading member in meridianal alignment with each other ofsubstantially the same geometrical dimension and weightcircumferentially about the axis of rotation of said means so that, whenrotated, a more uniform balance of said means is maintained.

FIGS. 9, l0 and 11 illustrate further modifications of the inventionwherein, in FIG. 9', a bellows 244 is used in the fixture 20' to replacethe spring-shaped coupler 148. The fixture 20 is otherwise identical tothe abovedescribed fixture 20 and, functionally, the arrangement of FIG.9 is identical to that of the fixture 20. The bellows 244 may be formedof pressed sheet metal or the like to the configuration shown in FIG. 9or, for ease and simplicity of construction, it might be fabricated inthe manner illustrated in FIG. 10. The structure of FIG. 10 comprises aplurality of flat rings 246 formed as punchings or the like from sheetsteel or other suitable metals and spaced from each other by interleavedwire rings 248 which space the flat rings 246 individually from eachother. The wire rings 248 are formed in two sizes, one group thereofbeing of a diameter only slightly less than the outside diameter of theflat rings 246 and the other group being of a diameter slightly greaterthan the inside diameter of the flat rings. The respective diameters ofthese wire rings being such as to permit them to lie between theadjacent or facing sides of the flat rings 246 when the rings 246 arestacked coaxially. This bellowstype of structure is fabricated bycoaxially stacking first a large diameter wire ring 248, a flat ring246, a small diameter wire ring 248 and so on. The wire and flat ringsare welded or otherwise secured together to complete the formation ofthe bellows.

An alternate form of bellows-type structure is shown in FIG. 11 whereinthe structure is shown as being extended or expanded for purposes ofillustration. This construction embodies only a plurality of identicallyshaped initially flat ring members 250 similar to the members 24-6 inFIG. 10. The flat ring members 250 are preferably formed of sheet steelor the like which may be spring-tempered and are stacked coaxially.Connections therebetween are made with rivets or the like 252 in themanner illustrated. That is, a first ring 250 is secured to a secondring 250 by rivets placed at two diametrically opposed locations thereonand the next ring 250 is secured to the second ring in similar fashionbut with the which is disposed at right angles to the diameter along 13which the first-mentioned connections were made. The connections of eachsuccessive ring 250' to its previously connected one are continued to bemade alternately along one diameter and then another disposed normal tothe previous one.

From the foregoing, it can be seen that simple, efficient and economicalmeans has been provided for accomplishing all of the objects andadvantages of the invention as expressed in the appended claims.Nevertheless, it should be understood that various changes in theconstruction and arrangement of parts may be made by those skilled inthe art without departing from the spirit of the invention and theinvention is not to be limited to the exact matters shown and describedas only preferred matters have been given for purposes of illustration.

Having described my invention, I claim:

1. A device for use in forming a compound curvature on a surface of awork member comprising a tool member having a working surface thereon ofthe shape desired to be formed on said surface of said work member, arotatable base plate, supporting means on said base plate adapted toreceive and support a first of said members fixedly for rotationtherewith, a resilient coupler encircling said supporting means andfirst member, said coupler having one of its ends fixed to said baseplate for rotation in unison therewith and holding means on the oppositeend of said coupler for receiving and supporting the second of saidmembers in adjacent relation with the first of said members and withgiven meridians of the respective surfaces of said members retainedsubstantially parallel to each other at all times during rotation ofsaid base plate and coupler carried thereby.

2. A device for use in forming a compound curvature on a surface of awork member comprising a tool member having a Working surface thereon ofthe shape desired to be formed on said surface of said work member, arotatable base plate, supporting means on said base plate adapted toreceive and support a first of said members fixedly for rotationsubstantially coaxially therewith, a resilient coupler embodying aplurality of superimposed spaced convolutes encircling said supportingmeans and first member when placed thereon, said coupler having one ofits ends fixed to said base plate for rotation in unison therewith andholding means on the opposite end of said coupler for receiving andsupporting the second of said members in adjacent relation with thefirst of said members and with given meridians of the respective surfaces of said members retained substantially parallel to each other atall times during rotation of said base plate and coupler carriedthereby.

3. A device for use in forming a compound curvature on a surface of awork member comprising a tool member having a working surface thereon ofthe shape desired to be formed on said surface of said Work member, arotatable base plate, supporting means on said base plate adapted toreceive and support a first of said members fixedly for rotationsubstantially coaxially therewith, a coupler having the configuration ofan open-ended bellows surrounding said supporting means and first memberwhen placed thereon, said coupler having one of its ends fixed to saidbase plate for rotation in unison therewith and holding means on theopposite end of said coupler for receiving and supporting the second ofsaid members in adjacent relation with the first of said members andwith given meridians of the respective surfaces of said members retainedsubstantially parallel to each other at all times during rotation ofsaid base plate and coupler.

4. A device for use in forming a compound curvature on a surface of awork member comprising a tool member having a working surface thereon ofthe shape desired to be formed on said surface of said work member, arotatable support, means on said support adapted to receive and hold afirst of said members fixedly and substantially coaxially with the axisof rotation of said support, a cylindrically shaped resilient couplersurrounding said first member normally in substantially coaxially spacedrelation therewith when said first member is placed on said means onsaid support, one end of said coupler being connected to said supportfor rotation in unison therewith and its opposite end being free to movelaterally relative to said support, holding means on said opposite endof said coupler for holding said second member with said surface thereofin adjacent facing relation to said surface of said first member andsaid holding means further embodying means for retaining given meridiansof the respective surfaces of said members substantially parallel toeach other at all times during rotation of said support and coupler.

5. A device for use in forming a compound] curvature on a surface of awork member comprising the combination of a tool member having a workingsurface thereon of the shape desired to be formed on said surface ofsaid work member, a rotatable base plate, means on said base plateadapted to receive and support a first of said members, a resilientcoupler rotatable with and carried by said base plate for supporting thesecond of said members with said surface thereof in adjacent relation tothe surface of said first member, said coupler embodying a plurality ofsuper-imposed substantially circular convolutes surrounding said firstmember in spaced relation therewith, said convolutes being constructedand arranged to move relatively freely to different spaced relationshipswith one another circumferentially thereabout substantially withoutorbital movement and means on said base plate and coupling means forholding said members with given meridians of their respective surfacesin fixed substantially parallel relation to each other at all timesduring movement of said convolutes to different spaced relationships.

6. Apparatus for forming a compound curvature on a surface of a workmember comprising the combination of a tool member having a workingsurface thereon of the shape desired to be formed on said surface ofsaid work member, a rotatable base plate, supporting means on said baseplate adapted to receive and support a first of said members, aresilient coupler rotatable with and carried by said base plate forsupporting the second of said members with said surface thereof inadjacent relation to the surface of said first member, said couplerembodying a plurality of superimposed convolutes surrounding said firstmember in spaced relation therewith, said convolutes being constructedand arranged to move relatively freely to different spaced relationshipswith one an other circumferentially thereabout substantially withoutorbital movement, means on said base plate and coupling means forholding said members with given meridians of their respective surfacesin fixed substtantially parallel relation to each other at all timesduring movement of said convolutes to different spaced relationships,means for rotating said base plate and means functioning simultaneouslyto move said second member laterally by controlled amounts relative tosaid first member during rotation of said base plate.

7. A device for use in forming a compound curvature on a surface of awork member comprising the combination of a tool member having a workingsurface thereon of the shape desired to be formed on said surface ofsaid work member, a rotatable base plate, means on said base plateadapted to receive and support a first of said members substantiallycoaxially with the axis of rotation of said base plate, a generallycylindrically shaped resilient coupler embodying a plurality ofsuperimposed annular sections integrally related with each other andresiliently adjustable to different spaced relationships about theircircumferences while being substantially immune to relative orbitalmisalignment, said coupler having one end fixed to said base plate insubstantially coaxial relation with the axis of rotation of said baseplate and having its opposite end free to move generally laterallyrelative to said base plate, holding means extending across saidopposite 1 5 end of said coupler for receiving and supporting the secondof said members with said surface thereof adjacent to and facing saidsurface of said first member and said holding means having provisionthereon for retaining given meridians of said surfaces of said first andsecond members substantially parallel to each other at all times.

8. A device for use in forming a compound curvature on a surface of awork member comprising the combination of a tool member having a workingsurface thereon of the shape desired to be formed on said surface ofsaid Work member, a rotatable base plate, means on said base plateadapted to receive and support a first of said members substantiallycoaxially with the axis of rotation of said base plate, an upstandingspring-shaped coupler embodying a plurality of superimposed convolutessurrounding said supporting means for said first member in spacedsubstantially coaxial relation therewith, the lowermost of saidconvolutes being fixed to said base plate to render said couplerrotatable in unison therewith, a yoke-like member fixed to the uppermostof said convolutes and arranged to extend substantially diametricallythereacross, means on said yoke-like member for holding the second ofsaid members with said surface thereof in adjacent facing relation tosaid surface of said first member when said first member is supported onsaid means adapted to receive the same and further means on saidyoke-like member for retaining given meridians of said respectivesurfaces of said members substantially parallel to each other at alltimes.

9. Apparatus for forming a compound curvature on a surface of a workmember comprising the combination of a tool member having a workingsurface thereon of the shape desired to be formed on said surface ofsaid work member, a rotatable base plate, supporting means on said baseplate adapted to receive and support a first of said members, anupstanding spring-shaped resilient coupler embodying a plurality ofsuperimposed spaced convolutes encircling said supporting means andfirst member when said first member is placed on said supporting means,the lowermost of said convolutes being fixed to said base plate torender said coupler rotatable in unison therewith, a yoke arranged uponthe uppermost of said convolutes so as to extend substantiallydiametrically thereacross, means on said yoke for holding the second ofsaid members with said surface thereof in adjacent facing relation tosaid surface of said first member, further means on said yoke forretaining given meridians of said respective surfaces of said memberssubstantially parallel to each other at all times, means for rotatingsaid base plate and means functioning simultaneously to move said secondmember laterally by controlled amounts relative to said first memberduring rotation of said base plate.

10. Apparatus for forming a compound curvature on a surface of a workmember comprising the combination of a tool member having a workingsurface thereon of the shape desired to be formed on said surface ofsaid work member, a rotatable base plate, supporting means on said baseplate adapted to receive and support a first of said members, anupstanding bellows structure encircling said supporting means and firstmember when said first member is placed on said supporting means, thelowermost end of said bellows structure being secured to said base plateto render said bellows structure rotatable is unison therewith, a yokearranged upon the uppermost end of said bellows structure so as toextend substantially diametrically thereacross, means on said yoke forholding the second of said members with said surface thereof in adjacentfacing relation to said surface of said first member, further means onsaid yoke for retaining given meridians of said respective surfaces ofsaid members substantially parallel to each other, means for rotatingsaid base plate and means functioning simultaneously to move said secondmember laterally by controlled amounts relative to said first memberduring rotation of said base plate.

11. A device for use in forming a compound curvature on a surface of awork member comprising the combination of a tool member having a workingsurface thereon of the shape desired to be formed on said surface ofsaid work member, a rotatable base plate, means on said base plateadapted to receive and support a first of said members substantiallycoaxially with the axis of rotation of said base plate, an upstandingbellows surrounding said supporting means for said first member inspaced substantially coaxial relation therewith, the lower- 'most end ofsaid bellows being fixed to said base plate to render said couplerrotatable in unison therewith, a yoke-like member fixed to the uppermostend of said bellows and arranged to extend substantially diametricallythereacross, means on said yoke-like member for holding the second ofsaid members with said surface thereof in adjacent facing relation tosaid surface of said first member when said first member is supported onsaid means adapted to receive the same and further means on saidyoke-like member for retaining given meridians of said respectivesurfaces of said members substantially parallel to each other at alltimes.

12. Surfacing apparatus for forming a compound curvature on a surface ofa work member with a tool member having a working surface thereon ofsubstantially the shape desired to be formed on said work membercomprising the combination of a base, a fixture rotatably supported onsaid base carrying said work and tool members, said fixture embodying asupport, means for holding a first of said members rigidly upon saidsupport so as to rotate in unison therewith, a resilient couplerencircling said first member and having one end attached to saidsupport, holding means on the opposite end of said coupler for holdingthe second of said members with said surface thereof in adjacentrelation with said surface of said first member and with given meridiansof the respective surfaces retained substantially parallel to eachother, means for rotating said fixture and actuating means arranged toengage said holding means on said resilient coupler for moving saidsecond member laterally relative to said first member simultaneouslyduring rotation of said fixture.

13. Surfacing apparatus for forming a compound curvature on a surface ofa work member with a tool member having a working surface thereon ofsubstantially the shape desired to be formed on said work membercomprising the combination of a base, a fixture rotatably supported onsaid base carrying said work and tool members, said fixture embodying abase plate, means for supporting a first of said members rigidly uponsaid 7 base plate so as to rotate in unison therewith, a resilientcoupler encircling said first member and having one end attached to saidbase plate, holding means on the opposite end of said coupler forholding the second of said members with said surface thereof in adjacentrelation with said surface of said first member and with given meridiansof the respective surfaces, of said members retained substantiallyparallel to each other, means for rotating said fixture, means operableeccentrically to the axis of rotation of said fixture adapted to engagesaid holding means on said coupler and operable to move said holdingmeans and second member laterally relative to said first membersimultaneously during rotation of said fixture, means for actuating saideccentric means, means for applying pressure upon one of said members ina direction generally toward the other of said members and means fordirecting a surfacing medium upon at least one of said surfaces of saidmembers.

14. Surfacing apparatus for forming a compound curvature on a surface ofa work member with a tool member having a working surface thereon ofsubstantially the shape desired to be formed on said work membercomprising the combination of a base, a fixture rotatably supported onsaid base carrying said work and tool members, said fixture embodying abase plate, means for supporting a first of said members rigidly uponsaid base plate so as to rotate in unison therewith, a resilientupstanding coupler embodying a plurality of superimposed integrallyrelated spaced convolutes encircling said first member and having oneend thereof attached to said base plate, said convolutes beingrelatively freely movable to different spaced relationships with eachother circumferentially thereabout, holding means on the opposite end ofsaid coupler for holding the second of said members with said surfacethereof in adjacent relation with said surface of said first member andwith given meridians of the respective surfaces retained substantiallyparallel to each other, means for rotating said fixture and actuatingmeans arranged to engage said holding means on said resilient couplerfor moving said second member laterally relative to said first membersimultaneously during rotation of said fixture.

15. Surfacing apparatus for forming a compound curvature on a surface ofa work member with a tool member having a working surface thereon ofsubstantially the shape desired to be formed on said work membercomprising the combination of a base, a fixture rotatably supported onsaid base carrying said work and tool members, said fixture embodying abase plate, means for supporting a first of said members rigidly uponsaid base plate so as to rotate in unison therewith, a resilient bellowsencircling said first member and having one end attached to said baseplate, holding means on the opposite end of said bellows for holding thesecond of said members with said surface thereof in adjacent relationwith said surface of said first member and with given meridians of therespective surfaces retained substantially 18 parallel to each other,means for rotating said fixture and actuating means arranged to engagesaid holding means on said resilient bellows for moving said secondmember laterally relative to said first member simultaneously duringrotation of said fixture.

16. A device for use in forming a compound curvature on a surface of awork member comprising the combination of a tool member having a Workingsurface thereon of the shape desired to be formed on said surface ofsaid WOIk member, a rotatable base, means on said base adapted toreceive and support a first of said members substantially coaxially withthe axis of rotation of said base, resilient coupler embodying aplurality of superimposed annular sections so joined With each other asto be resiliently adjustable to different spaced relationships abouttheir circumferences while being substantially immune to relativeorbital misalignment, said coupler having one end fixed to said base insubstantially coaxial relation with the axis of rotation of said baseand having its opposite end free to move generally laterally relative tosaid base, holding means extending across said opposite end of saidcoupler for receiving and supporting the second of said members withsaid surface thereof adjacent to and facing said surface of said firstmember and said holding means having provision thereon for retaininggiven meridians of said surfaces of said first and second memberssubstantially parallel to each other at all times.

References ited in the file of this patent UNITED STATES PATENTS1,135,936 Edmondson Apr. 1 3, 1915 1,217,090 Growlland Feb. 20, 19171,287,479 Simpson Dec. 10, 1918

1. A DEVICE FOR USE IN FORMING A COMPOUND CURVATURE ON A SURFACE OF AWORK MEMBER COMPRISING A TOOL MEMBER HAVING A WORKING SURFACE THEREON OFTHE SHAPE DESIRED TO BE FORMED ON SAID SURFACE OF SAID WORK MEMBER, AROTATABLE BASE PLATE, SUPPORTING MEANS ON SAID BASE PLATE ADAPTED TORECEIVE AND SUPPORT A FIRST OF SAID MEMBERS FIXEDLY FOR ROTATIONTHEREWITH, A RESILIENT COUPLER ENCIRCLING SAID SUPPORTING MEANS ANDFIRST MEMBER, SAID COUPLER HAVING ONE OF ITS ENDS FIXED TO SAID BASEPLATE FOR ROTATION IN UNISION THEREWITH AND HOLDING MEANS ON THEOPPOSITE END OF SAID COUPLER FOR RECEIVING AND SUPPORTING THE SECOND OFSAID MEMBERS IN ADJACENT RELATION WITH THE FIRST OF SAID MEMBERS ANDWITH GIVEN MERIDIANS OF THE RESPECTIVE SURFACES OF SAID MEMBERS RETAINEDSUBSTANTIALLY PARALLEL TO EACH OTHER AT ALL TIMES DURING ROTATION OFSAID BASE PLATE AND COUPLER CARRIED THEREBY.